Extended roller guide for elevators



W. H. BRUNS EXTENDED ROLLER GUIDE FOR ELEVATORS April 30, 1963 FiledOct. 7, 1959 WILL/AM HEHPYBFUNS INVENTOR United States Patent Cft'ice3,087,583 Patented Apr. 30, 1963 3,d87,583 EXTENDED ROLLER GUIDE FORELEVATORS William Henry Bruins, Lincolndale, N.Y., assignor to OtisElevator Company, New York, N.Y., a corporation of New Jersey Filed Oct.7, 1959, Ser. No. 845,022 11 Claims. (Cl. 187-95) This invention relatesto guides for bodies movable in a vertical path and more specificallyrelates to resilient guides for elevator cars operating in hoistways.

Elevator cars usually operate in hoistways in which on two oppositesides thereof there are attached metallic T- shaped guide rails. Thesecooperate with guides that are aflixed to the sides of the car near itstop and bottom extremities to control the lateral movement of and toguide the car in its passage through the hoistway. When these guidesencounter a misalignment of the guide rails, which misalignment may be adiscontinuity between adjacent sections of rail or a bowed or twistedsection of one or more rail sections, the car is forced from itsintended path with subsequent horizontal forces being exerted on itsload or passengers. The magnitude of these forces is a function of thespeed of the car and the degree of misalignment of the rails. Thus theeffect of misalignment of the rails is generally much more pronounced inrelatively high speed elevators than in those of lower speed.

The guides may be either of the sliding shoe type or the rolling wheeltype, the latter being termed roller guides. In this latter type, therolling wheels are resiliently mounted and cooperate with the threeguiding surfaces of each rail to constrain the car in its travel path.Guides of this general type are shown in Patents #1,854,976 to F. Bradyand #2,l00,l69 to Clifford Norton. In these types of guides, the wheelsare mounted on axles which permit the rim of the wheel to run on theguide rail surface and the wheel assembly is resiliently biased intocontact with the guide rail surface by one or more springs. Inasmuch asthe clearances between the guide rail surface and adjacent portions ofthe elevator car are not unlimited, there is associated with each wheela stop or stud which limits the amount the Wheel may be pushed back asthe car tends to move laterally.

In addition to the rollers or wheels, the stops and the resilientmountings, these roller guides include a pedestal or standard by whichthe entire guide assembly is rigidly afixed to the car assembly.Generally, but not necessarily always, these roller guides have beenrigidly affixed to the top and bottom of the car sling near the edge ofthe car such that the rims of the guide wheels contact the respectivesurfaces of the guide rails with a force that is determined by thestiffness of the resilient spring mounting which urges the wheel forwardto its position of engagemerit.

From what has been said heretofore, it will be evident that the degreeof straightness of the guide rails contributes directly to thesmoothness of the ride as the elevator car traverses its intended path.To a certain extent the straightness of these guide rails is related tothe degree of care taken in their manufacture and in their subsequenthandling in being affixed to the hoistway sides. Generally speaking,this care is reflected in cost; the greater the degree of care, thegreater the cost of providing the rails. Within bounds, the need forproviding perfectly aligned guiding rails can be reduced by using rollerguides arranged according to this invention such that the effects ofmost if not all discontinuities in the rails are masked by thecushioning action of the roller guide.

It is, therefore, an object of this invention to improve the ridingquality of elevator cars which use roller guides running on the surfacesof guide rails.

It is also an object of this invention to effect this improvement inriding quality by improving the roller guide unit and without entailingthe necessary expense for effecting a corresponding improvement by careof manufacture and installation of the rails.

It is a further object of the invention to achieve these improved ridingqualities in the car while at the same time tolerating somewhat greatermisalignment of the guide rails than has heretofore been thought to bepossible.

The invention is featured by a much larger separation between the axisof rotation of the resiliently mounted guide wheels or rollers .and thepoint of aflixing the standard or pedestal to the car or sling.

The invention is also featured by divorcing the roller guide and itsassociated inflexible stop, with the result that the roller guide may bedisplaced from its usual position to a considerably greater degree thanhas heretofore been possible with prior art guides.

The invention is further distinguished by the provision of means foroptionally changing or optimally adjusting the constant of deformation,which will hereafter be referred to as the spring constant, of thespring which resiliently urges each wheel into contact with itsconjugate rail surface. In this arrangement, changes in the springconstant can be made with or independently of changes in the pressurewith which the spring biases its associated roiling wheel.

Further and additional characteristics and advantages of the inventionwill be gained from the following explanation of a preferred embodimentof the invention when taken in conjunction with the drawings in which:

FIGURE 1 is a schematic view of an elevator installation showing anelevator car equipped with the guiding means of the present invention;

FIGURE 2 is a partially enlarged side elevation of the upper left guidemeans illustrated in FIGURE 1;

FIGURE 3 is a sectional view of FIGURE 2 taken along line 3-3;

FIGURE 4 is a plan view of FIGURE 2;

FIGURE 5 is an enlargement of a guide spring assembly;

FIGURE 6 is a schematic side elevation showing another embodirnent ofthe invention; and

FIGURE 7 is a section taken along line 77 of FIG- URE 6.

Referring to FIGURE 1, an elevator car 10 is shown supported by a carsling 11 to which roping 13 is secured for raising and lowering the carin the hoistway. Guide rails 12 having a base 14 and stem 16 areprovided on each side of the hoistway. The guide rails are T-shaped incross section and have side surfaces and an end surface on the stem 16for cooperation with roller guides designated as a unit by numeral 18mounted on the upper and lower cross members of car sling 11. As theroller guide units 18 are of identical construction, only a single(guide and the operation thereof will be described in etai Referring toFIGURE 2, the roller guide 13 according to the preferred construction,comprises a guide stand 2% ggapted to mount, as by bolting, a guideroller assembly The guide stand 20 comprises an elongate member 24vertically mounted on a base 26. The guide stand is secured to the carsling 11 as by bolts through bolt holes in the base. An aperture 28extends horizontally into the base for receiving the guide rail stem 16(see FIG- URE 3).

Referring to FIGURES 2 and 3, the elongate member 24 is provided with avertical slot 30 to accommodate the back portion of the roller stop 34that contacts the end guide surface of rail stem 16. Right anglebrackets 32 are secured, as by welding, to the 'base 26 and along thesides of slot 30 to the vertical member 24. Roller stops 34, one foreach guide surface of guide rail stem 16, are inflexibly mounted on thebrackets 22 in eccentric mountings. A roller stop extends into slot 30and all roller stops extend into aperture 28. Each roller stop isadapted for adjustment on its eccentric mounting to the permissiblefloat distance 1'' (FIGURE 1) from the associated guide surface. Thefloat distance f is the horizontal distance to which the transversemovement of the car is limited in order to prevent the adjacent parts ofthe car from sliding or rubbing on the guide rail surfaces.

At the top of the vertical member 24 a capital 36 is provided on whichguide roller assembly 22 is mounted.

Referring to FIGURES 2 and 4, the guide roller assembly 22 comprises abase plate 38 which is secured to the capital 36, as by bolts throughholes in both plates. On the base plate 38 are formed pedestals 40, 42and 44. Pedestals 40 and 42 are adjacent the guide rail and are locatedon opposite sides of stem position 16 and parallel to the base 14 ofguide rail 12. Pedestal 44 is to the rear of and adjacent to pedestal40. The last mentioned two pedestals are in a line parallel to the guiderail stem 16, with pedestal 40 adjacent the guide rail. Oppositelydisposed spring guide bolts 46 are horizontally mounted parallel toguide rail base 14 near the tops of pedestals 40 and 42. Pedestal 40also mounts a spring guide bolt 46 extending towards pedestal 44parallel to the guide rail stem 16. A rocker arm 48 is pivotallysupported at its lower end by each pedestal and carries a guide roller50 for engaging one of the guiding surfaces of the guide rail stem 16.The upper end of each rocker arm 48 terminates in a spring seat 52 whichis pierced to allow the passage of spring guide bolts 46. Spring guidebolts 46 are threaded for most of their lengths and respectively engagespring adjusting nuts 54 and lock nuts 56. Springs 58, intermediatespring seats 52 and spring adjusting nuts 54, bias respective rockerarms 48 thereby bringing the rollers 50, carried by the rocker arms 48,into rolling engagement with the respective guide surfaces of guide railstem 16.

Referring to FIGURE 5, the spring adjusting nut 54 is grooved exteriorlyto engage the helices of spring 58 and is tapped to engage the threadsof spring guide bolt 46. The spring adjusting nut 54 by rotation canthus be moved relative to the length of the spring 58 and of the springguide bolt 46. A lock screw 60 and washer 62 locks the adjusting nut 54at any point on the spring 58, and lock nut 56 locks the adjusting nut54 at any point on the spring guide bolt 46. Changing the position ofthe adjusting nut 54 with respect to the length of the unstressed spring58 changes the springs effective length and therefore its springconstant. The spring constant is equal to the ratio of the applied loadto the change in deformation or length of the spring caused by the load,provided the load does not exceed the springs elastic limit. Changingthe position of adjusting nut 54 with respect to the spring guide bolt46, while locked by lock screw 60 and Washer 62 to the spring '58,affects the pressure with which the spring, acting through rocker arm48, biases the guide roller against the guide rail stem 16.

In actual practice, and in several tested embodiments of the invention,elongate member 24 is at least one foot in length. The exact length ofthis member will be subject to the structural characteristics of a giveninstallation. In one tested embodiment, and because of the structurallimitations, the elongate members 24 for the rolling guides on top ofthe car were each about 24 in length. Those for the bottom guides wereeach about 36" in length. While the length of these elongate members 24is not necessarily critical and may vary in one installation from thosein another, it is a general rule that the longer this member is made thesofter may be guide spring 58 which is used; that is, the lower is thespring constant of guide spring 53. Thus, a relatively Weak or softspring acting at the end of an elongate member 24 of a given length isequally as eifective in holding the car to a predetermined path ofmovement as would be a relatively hard or stronger spring acting at theend of an elongate member 24 of a shorter length.

The roller stops 3-2 being mounted substantially adjacent to the top andbottom of car sling 1=1 operate to limit the transverse excursion of thecar to the predetermined float distance f (FIGURE 2) but permit thesprings to be compressed a greater distance than would be the case ifthe stops were mounted closer to the guide rollers 50. These rollerstops 32 are located between their associated guide rollers 50 and theportions of the car which when at rest most closely approach the guiderails 12. Preferably, the stops are placed at or near the part of thecar adjacent the door operating mechanism at the top of the car andadjacent the safety brake at the bottom of the car. As a practicalmatter of convenience they may be located on the top and bottom of thecar sling 11, as illustrated in FIGURE '1.

In addition to the foregoing, the invention provides means foroptionally adjusting the spring constant of springs 58 by positioningspring adjustment nuts 54 to increase or decrease the springs effectivelength. This is in addition to the provision of means for increasing ordecreasing the stress in spring 58 and consequently the pressure exertedby it in changing the position of adjusting nut 54 with respect to itsguide bolt 46 while locked to the spring by bolt 60 and washer 62.

It has been determined that the energy at a guide roller that jars orshakes the car is directly proportional to the spring constant of thatguide roller spring and the square of the displacements of theassociated guide rail from alignment. Thus, for any given raildisplacement, reducing the spring constant will reduce this energy.However, the spring must be strong enough, i.e., have a spring constantsufliciently high, ordinarily to prevent the car stops 34 from cominginto contact with the guide rails. The stops 34, as stated before, markthe limit to which the car is allowed to move transversely with respectto its guide rails and this distance is designated the float distance 7'(FIGURE l).

For maximum utility of the invention springs 58 should be adjusted forand maintained at the minimum spring constants and pressures that aresulficicnt to prevent the cars roller stops 34 from riding the guiderail surfaces under the usual load conditions. This may be accomplishedas follows. With no load in the car, the roller stops 34 at the top andbottom of the car should be adjusted by means of their eccentricmountings to the permissible horizontal float distance f. In practicethe springs for the guides on the top of the car are adjusted before thesprings for the guides on the bottom of the car. It should be noted thatthe top guide springs 58 are adjusted with the bottom guide springs 58inoperative and that the bottom. guide springs 58 are adjusted with thetop springs 58 operative. However, the procedures are the same andtherefore only those for adjusting the top guide springs are described.

Referring to FIGURE 5, the springs 58 are adjusted for their minimumconstants and pressures, i.e., the spring adjusting nuts 54 are lockedat the ends of the spring guide bolts 46 and at the ends of the springs58. An eccentric load sufficient to bring the roller stops 34 hardagainst the guide rails 12 is introduced first on one side of the carand then on the other. The pressures of the spring 53 are increased ifnecessary to keep their respective associated and opposed guide rollers50 in contact wtih the guide rail 12 for the entire length of travel ofthe car in its hoistway. The procedure is repeated with the eccentricload in the front of the car and then in the rear in order to adjust thepressures of the remaining opposing top springs for keeping theirrespective guide rollers 50 in contact with the guide rail surfaces. Ineach case spring pressures are increased by rotating on guide bolts 46the respective spring adjusting nut 54 while locked to spring 58 bymeans of lock screw 60 and washer 62. Spring adjusting nut 54 is lockedin position on guide bolt 46 by means of lock nut 56. The eccentric loadsuflicient to bring the roller stops hard against the guide rails is nowreplaced by an expected eccentric load which is introduced first on oneside and then on the other side of the car. If the car rides its stops34 on one side only, the opposing springs 58 may be strong enough, i.e.,the constant sufficiently high, but the spring pressure must beincreased on the stop riding side of the car until the car rides justclear of the stops 34 on that side. The load is then shifted to theother side of the car and if the car rides just clear of its associatedstop 34 on that side, the adjustments for these springs are completed.If the car does not clear the stop 34, then the spring constant may beincreased or if the car more than rides just clear, the spring constantsmay be decreased. The constant of a spring 53 is changed by rotating theassociated spring adjusting nut 54 with respect to the spring 58, thatis rotating it with the lock screw 60 and the lock washer 62 loose andlock nut 56 unengaged. The spring adjusting nut 54 under thesecircumstances moves along the helices of the spring 58 and adds orsubtracts turns to the effective length of the spring 58, depending onthe direction of rotation. The spring constant is decreased when turnsare added and increased when turns are subtracted from the effectivelength of the spring. Constants are corrected, either added orsubtracted, and pressure is adjusted until the car l0'travels just clearof the stops 34 with the expected eccentric load on one side then on theother side of the car. After any change of spring constant the car 10 isdeflected to its associated opposing stops 34 and spring pressureadjusted to keep the associated rollers 50 in contact with theirrespective guide rail surfaces on guide rail stem 16.

If the car 10 rides the stops 34 on both sides, the associated springs'58 are too weak and their constants are increased by moving theiradjusting nuts 54 nearer the middle of the unstressed springs 58 andresetting the spring pressures as before. This is done as previouslyexplained and the spring constants and pressures are readjusted untilthe car 10 rides clear of the stops 34 on both sides of the car 10 withthe expected eccentric load on one side and then on the other.

This procedure is repeated with the expected eccentric load in the frontand then in the back of the car to determine and set the springconstants and pressures of the springs for the rollers engaging the sidesurfaces of the guide rail stem 16.

The top guide springs 58 are now adjusted to minimum spring constant andpressure and a minimum amount of energy is available to shake or jar thecar as its guides travel over the misaligned guide rails. The bottomguide springs 58 are adjusted in the same manner to complete theadjustment for the car.

FIGURES 6 and 7 illustrate a portion of another embodiment of theinvention. The guide stand 68 as a whole comprises a base 70 which boltsto the car sling 11. The base 70 has a slot 72 to receive the guidingsurfaces of the guide rail stem 16. The sides and end of slot 72 act asstops 74, said sides and end being the allowable float distance from theguiding surfaces. The pedestal 76 on the base 70 is adjacent the slot 72and in the same vertical plane as the guide rail stem 16 and slot 72.The flexible upright member '78 is fastened to the pedestal 76 as bybolts 80'. The guide roller 82 is secured to the free end of theflexible member 78 and is adapted to engage rotatively one surface ofthe guide rail stem 16. Two vertical channel members 84 are welded tothe base 70 adjacent pedestal 76 which is intermediate the channelmembers 84 and the slot 72. The channel members 84 are symmetricallyarranged to form a partial enclosure 86 with channels parallel andfacing across a vertical plane that bisects the guide rail stem 16, theroller 82, the flexible upright member 78 and the slot '72. Theadjusting block 88 is enclosed by the channel members 84 and adapted toslide between them. The adjusting block is horizontally center tapped toreceive .the biasing head bolt 90, the ends of which extend beyond theblock 88 and between and beyond the channel members 84 which were leftseparated for the purpose. Lock nut 92 is carried by bolt 90intermediate the bolt head 94 and the channel members 84 and serves tolock the bolt $0 at any point of its length and also serves to lock theblock 88 at any point on the channel members 84. The end of bolt 90biases the flexible member 7 8 to bring the guide roller 82 into contactwith the guide rail stem 16. The spring constant of the flexible uprightmember 78 is adjustable by moving the block 88 up or down between thechannel members 84. The spring pressure is adjustable by rotating bolt90 in block 88 to increase or decrease the bias on the flexible member78. Stationary stops or rolling ones similar to stops 34 in thepreferred embodiment can alternatively be incorporated in the base 70 ofthe guide stand 68.

As many changes can be made in the above described construction and manyapparently different embodiments of this invention can be made withoutdeparting from the scope thereof, it is intended that all mattercontained in the above description or shown on the accompanying drawingsbe interpreted as illustrative only and not in a limiting sense.

What is claimed is:

1. A roller guide adapted for mounting on an elevator car for use with avertically positioned guide rail having guiding surfaces to guide theelevator car in its hoistway, said guide comprising; a mounting memberhaving a base and an elongated vertical section, said base being adaptedfor rigid connection to a structural member of said car adjacent saidrail in such manner as to receive the guiding surfaces of said railwithin its confines; a plurality of guide rollers, one each for normalengagement with each guide surface of said rail, each said guide rollerbeing rotatably and pivotally mounted on said elongated member; a springfor each of said guide rollers, each said spring being positioned so asto bring its associated roller in rolling contact with a respectiveguide surface when said guide rail is normally positioned within theconfines of said base infiexibly mounted stops, one for each guidesurface, mounted on said base and adapted to prevent contact betweensaid guide rail and base; and means associated with each said spring foradjusting the pressure with which said guide roller bears on itsrespective guide surface, each of said guide rollers being separatedfrom said mounting base and its associated inflexibly mounted stop by avertical linear distance in excess of twelve inches.

2. A roller guide adapted for mounting on an elevator car for use with avertically positioned guide rail having three guiding surfaces forguiding the elevator car in its hoistway, said guide comprising; amounting member having a base and an elongated stand mounted on saidbase, said base being adapted for rigid connection to a structuralmember of said car adjacent said rail and being apertured to receive theguide surface portions of said rail within its boundaries; a pluralityof guide rollers pivotally mounted on said stand, one for normalengagement with each guide surface in a rolling contact when engagingsaid surface; a spring connected to each said guide roller urging saidroller into contact with its respective guide surface; and a pluralityof inflexible stops, one for each guide roller, mounted intermediate therespective guide roller and said car and adapted to limit thedisplacement of said guide roller, each said stop being displacedvertically from the axis of rotation of its respective guide roller by adistance in excess of one foot.

3. A roller guide for .use with an elevator car and a guide rail havinga plurality of guide surfaces, said roller guide comprising; a baseadapted for rigidly attaching said roller guide to said elevator carstructure adjacent said guide rail; an elongate member verticallysupported by said base; a plurality of guide rollers pivotally mountedon said member, each said guide roller being adapted to engage arespective one of said guide surfaces rotatably when displaced to itabout its pivot; a plurality of inflexible stops mounted between saidguide rollers and said car and adapted to limit the displacement of saidguide rollers; a spring adapted to displace flexibly each said guideroller about its pivot to engage the respective guide surface; and meansfor adjusting the constant of deformation of each of said springs to beinversely related to the distance between its associated stop and guideroller, said associated stop and guide roller being separatedsubstantially one foot.

4. A roller guide for use with elevator cars and guide rails having aplurality of guide surfaces, said roller guide comprising; a base forrigidly attaching said roller guide to said elevator car structureadjacent said guide rail; an elongate member vertically supported bysaid base; a plurality of guide rollers pivotally mounted on saidmember, said guide rollers being adapted to engage said guide railsurfaces rotatably when displaced toward them about said pivots, aplurality of inflexible stops one each mounted intermediate each pivotedguide roller mounting and said car structure and adapted to limitdisplacement of its associated guide roller; and a spring individual toeach guide roller adapted flexibly to displace said roller about itspivot to engage its respective guide rail surface; each said springincluding means for increasing or decreasing its effective length andeach said associated stop and guide roller pivot being separated notless than one foot.

5. A roller guide for use with an elevator car and a guide rail having aplurality of guide surfaces, said roller .guide comprising; a baseadapted for rigid attachment to said elevator car structure adjacentsaid guide rail and 'an elongate member attached to and verticallysupported by said base, a plurality of guide rollers pivotally mountedon said elongate member, each said guide roller being adapted rotatablyto engage a respective one of said guide surfaces when displaced aboutits pivot so as to contact said surface, a plurality of springs, one foreach guide roller, adapted to move its associated roller into contactwith one of said guide surfaces, a plurality of inflexible stops, oneeach mounted between said base and a respective one of each of saidpivotal guide roller mountings, said stops each being in the form of arotatable wheel inflexibly mounted separately from said guide rollerpivotal mounting to engage a respective guiding surface of said rail inrolling engagement as said guide surface deflects its associated guideroller a predetermined amount, the axis of rotation of associated guiderollers and rotatable stops being separated by more than eleven inches.

6. A roller guide for use with elevator cars and guide rails having aplurality of guide surfaces, said roller guide comprising; a base forrigidly attaching said roller guide to said elevator car structureadjacent said guide rail; a

vertical stand supported by said base; a plurality of guide rollerspivotally mounted on said stand; a plurality of springs, one for each ofsaid rollers, adapted to move its roller to a forward position about itspivot, said guide rollers being adapted to engage said guide railsurfaces rotatably when so moved; a plurality of inflexible roller stopsone each being rotatably mounted intermediate the pivot mounting of eachguide roller and said base removed from said pivot substantially onefoot or more and respectively adapted to limit the displacement of saidguide rollers about their pivots; each of said springs having a springconstant which is adjustable manually to be inversely related to thedistance between its guide roller and its associated roller stop as thisdistance progressively exceeds one foot.

7. A guide for an elevator car adapted for use with a verticallydisposed guide rail having a plurality of guide surfaces comprising, aplurality of pivotally mounted rollers, one for each guide surface, aplurality of springs, one for each pivotally mounted roller and mountedto force its roller into yielding rolling engagement with its associatedguide surface, a standard adapted to support said spring biased rollersin vertical displacement from the car, said standard having a recessedbase adapted for rigid connection to the car structure and to receivesaid guide surfaces within its recess, and a plurality of unyieldingstops, one for each guide surface, mounted adjacent said recess andacting to engage said rail surfaces to prevent their engagement withsaid base and car structure, said rollers and said stops beingvertically separated by a distance greater than 11 inches.

8. A guide for an elevator car adapted for use with a verticallydisposed guide rail having a plurality of guide surfaces comprising apivotally mounted roller contiguous to each surface, a spring individualto each roller and mounted for reaction with its pivoted roller tomaintain said roller in yielding rolling engagement with its associatedguide surface, each said spring being adapted for manual change of itsconstant of deformation, a standard adapted to support said springbiased rollers in vertical displacement from the car and being itselfadapted for rigid connection to the car structure, a plurality ofunyielding stops, one for each guide surface, mounted intermediate saidcar structure and said pivotally mounted rollers and acting to limit theamount by which said rollers may be deflected by the guide rail, saidmanually adjustable spring constant means also providing means forvarying the pressure with which each said pivotally mounted roller isforced against its conjugate guide surface.

9. An elevator guide in accordance with claim 8 wherein each unyieldingstop is a roller mounted for rotation on an axis parallel to the face ofits conjugate guide surface.

10. In an elevator installation; a hatchway; a body movable therein; aguide rail for said movable body; a support carried by said movablebody; a plurality of rollers, one for each of the guiding surfaces ofthe guide rail, said rollers rolling upon their respective guidingsurfaces to guide said body in its movement in said hatchway; aresilient support for each roller, said supports being mounted on saidfirst named support; and means acting through said supports to maintaintheir corresponding roller in yielding rolling contact with said guidingsurfaces; each of said means being arranged for manual adjustmentvarying the constant of deformation of the resilient support.

11. In an elevator installation; a hatchway; a body movable therein; aguide rail for said movable body; a support carried by said movablebody; a plurality of rollers, one for each of the guiding surfaces ofthe guide rail, said rollers rolling upon their respective guidingsurfaces to guide said body in its movement in said hatchway; a supportfor each roller, said supports being pivotally mounted on said firstnamed support; and a helical spring for each of said rollers, saidsprings acting through said supports to maintain their correspondingroller in yielding rolling contact with said guiding surfaces and eachof said springs having associated with it an exteriorly grooved nutengaging the helices of said spring and means for adjusting manually theeffective length of said spring by adjustment of said nut along thelongitudinal dimension of said spring.

References Cited in the file of this patent UNITED STATES PATENTS1,098,956 Miller June 2, 1914 1,713,165 Bridge May 14, 1929 1,854,976Brady Apr. 19, 1932 2,100,169 Norton Nov. 23, 1937 2,248,447 Wood July8, 1941 2,308,210 Sahlin Jan. 12, 1943 2,704,696 Rasmussen Mar. 22, 1955FOREIGN PATENTS 784,798 Great Britain Oct. 16, 1957

1. A ROLLER GUIDE ADAPTED FOR MOUNTING ON AN ELEVATOR CAR FOR USE WITH AVERTICALLY POSITIONED GUIDE RAIL HAVING GUIDING SURFACES TO GUIDE THEELEVATOR CAR IN ITS HOISTWAY, SAID GUIDE COMPRISING; A MOUNTING MEMBERHAVING A BASE AND AN ELONGATED VERTICAL SECTION, SAID BASE BEING ADAPTEDFOR RIGID CONNECTION TO A STRUCTURAL MEMBER OF SAID CAR ADJACENT SAIDRAIL IN SUCH MANNER AS TO RECEIVE THE GUIDING SURFACES OF SAID RAILWITHIN ITS CONFINES; A PLURALITY OF GUIDE ROLLERS, ONE EACH FOR NORMALENGAGEMENT WITH EACH GUIDE SURFACE OF SAID RAIL, EACH SAID GUIDE ROLLERBEING ROTATABLY AND PIVOTALLY MOUNTED ON SAID ELONGATED MEMBER; A SPRINGFOR EACH OF SAID GUIDE ROLLERS, EACH SAID SPRING BEING POSITIONED SO ASTO BRING ITS ASSOCIATED ROLLER IN ROLLING CONTACT WITH A RESPECTIVEGUIDE SURFACE WHEN SAID GUIDE RAIL IS NORMALLY POSITIONED WITHIN THECONFINES OF SAID BASE INFLEXIBLY MOUNTED STOPS, ONE FOR EACH GUIDESURFACE, MOUNTED ON SAID BASE AND ADAPTED TO PREVENT CONTACT BETWEENSAID GUIDE RAIL AND BASE; AND MEANS ASSOCIATED WITH EACH SAID SPRING FORADJUSTING THE PRESSURE WITH WHICH SAID GUIDE ROLLER BEARS ON ITSRESPECTIVE GUIDE SURFACE, EACH OF SAID GUIDE ROLLERS BEING SEPARATEDFROM SAID MOUNTING BASE AND ITS ASSOCIATED INFLEXIBLY MOUNTED STOP BY AVERTICAL LINEAR DISTANCE IN EXCESS OF TWELVE INCHES.